unrelated cleanup

Author: kadiwa4

compiler/rustc_lint/src/builtin.rs

@@ -104,19 +104,11 @@ declare_lint! {
 
 declare_lint_pass!(WhileTrue => [WHILE_TRUE]);
 
-/// Traverse through any amount of parenthesis and return the first non-parens expression.
-fn pierce_parens(mut expr: &ast::Expr) -> &ast::Expr {
-    while let ast::ExprKind::Paren(sub) = &expr.kind {
-        expr = sub;
-    }
-    expr
-}
-
 impl EarlyLintPass for WhileTrue {
     #[inline]
     fn check_expr(&mut self, cx: &EarlyContext<'_>, e: &ast::Expr) {
         if let ast::ExprKind::While(cond, _, label) = &e.kind
-            && let ast::ExprKind::Lit(token_lit) = pierce_parens(cond).kind
+            && let ast::ExprKind::Lit(token_lit) = cond.peel_parens().kind
             && let token::Lit { kind: token::Bool, symbol: kw::True, .. } = token_lit
             && !cond.span.from_expansion()
         {
@@ -2688,7 +2680,7 @@ impl<'tcx> LateLintPass<'tcx> for InvalidValue {
 }
 
 declare_lint! {
-    /// The `deref_nullptr` lint detects when an null pointer is dereferenced,
+    /// The `deref_nullptr` lint detects when a null pointer is dereferenced,
     /// which causes [undefined behavior].
     ///
     /// ### Example